Stevia blends containing rebaudioside B

ABSTRACT

The present invention relates to the use of sweet steviol glycoside compounds, particularly rebaudioside B, in sweetening compositions. Sweetening compositions comprising selected amounts of rebaudioside B have been shown to possess favorable flavor profiles when compared to other high intensity sweetener compounds and are useful in the preparation of consumables.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a non-provisional application claiming thebenefit of U.S. Provisional Patent Application Ser. No. 61/437,390,filed Jan. 28, 2011, which is incorporated herein by reference in itsentirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND

Natural caloric sweeteners, such as sucrose, glucose, and fructose,possess desirable taste characteristics, but they add to the caloriccontent of products. Therefore, there is great consumer interest in lowor non-caloric sweeteners that are considered as healthier alternatives.Non-caloric natural and synthetic high-potency sweeteners are known, butthey most often possess flavor profiles that are not as desirable toconsumers as sugars. Thus, it is desirable to develop non-caloricsweeteners that can be substituted for sugar and that have a moredesirable taste profile.

The species Stevia rebaudiana (“Stevia”) is the source of certainnaturally occurring sweet steviol glycosides. Considerable research anddevelopment has been done to evaluate the use of sweet steviolglycosides of Stevia as non-caloric sweeteners. Sweet steviol glycosidesthat may be extracted from Stevia include the six rebaudiosides (i.e.,rebaudioside A to F), stevioside (the predominant glycoside in extractsfrom wild type Stevia), and dulcosides.

Commercial low or non-caloric sweeteners based on rebaudioside A andother steviol glycosides tend to have bitter and licorice aftertastes.These characteristics are especially notable at concentrations aboveabout 300 ppm. In food applications, preferred use levels (8-10% sugarequivalence values) are typically about 500 ppm to about 1000 ppm, abovethe range at which off tastes are first noticed. Thus a need continuesto exist for reduced-, low-, and/or non-caloric sweeteners comprisingsweet steviol glycosides that have taste profiles with reduced or nobitterness, undesirable flavors (e.g., licorice), or sweetness profilesmore like natural caloric sweeteners, or combinations of suchproperties.

SUMMARY OF THE INVENTION

The present invention is directed to a Stevia extract comprisingrebaudioside B at a concentration that is in the range of 10 to about90% by weight of the Stevia extract.

The present invention is also directed to a sweetening compositioncomprising sweet steviol glycoside compounds, wherein the sweet steviolglycoside compounds comprise rebaudioside B at a concentration that isin the range of 10% to about 90% by weight of the total amount of sweetsteviol glycoside compounds in the sweetening composition.

The present invention is also directed to consumables such as beverages,foodstuffs, oral care products, tobacco products, pharmaceuticalproducts, and nutraceutical products comprising the foregoing sweeteningcompositions and methods of the sweetening the same using the foregoingsweetening compositions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the solubility of rebaudioside B in citricacid buffer at pH of 3 as a function of rebaudioside A and steviosideconcentrations.

FIG. 2 shows the structures of steviol glycosides.

FIG. 3 is a graph showing the effect of rebaudioside B content (in asolution containing rebaudioside A and added rebaudioside B for a totalconcentration of 900 ppm in water) on various flavor attributes asscored by taste panelists.

DETAILED DESCRIPTION I. Definitions

As used herein, the phrase “sweet steviol glycoside compounds” means anyof a number of naturally occurring compounds with a general structure ofthe steviol diterpene ring system with one or more saccharide residueschemically attached to the ring.

II. Overview

It has unexpectedly been discovered that by including and/or controllingthe concentration of rebaudioside B in Stevia extracts and sweeteningcompositions comprising sweet steviol glycosides tends to reduce oreliminate taste characteristics generally considered to be negative suchas bitterness, licorice aftertaste, or result in a sweetness profilemore like that of natural caloric sweeteners, or combinations of suchproperties. Specifically, it has been discovered that the foregoingbenefits may be achieved by selecting a relatively high concentration ofrebaudioside B with respect to the total concentration of sweet steviolglycosides in the Stevia extract and sweetening composition (e.g., atleast 10% by weight of the total amount of sweet steviol glycosidecompounds being rebaudioside B).

The aforementioned Stevia extracts and sweetening compositions of thepresent invention are useful as reduced-caloric, low-caloric, ornon-caloric sweeteners in foodstuffs, i.e., edible or chewablecompositions such as food, beverages, medicine, candy, chewing gum, andthe like. It has been discovered that the Stevia extract and sweeteningcompositions of the present invention can possess a sweetness profilethat is more sugar-like, reduced bitter aftertaste, reduced off flavors(e.g., licorice) than other mixtures of sweet steviol glycosides, suchas commercially available blends and mixtures of steviol glycosides.Testing has shown that, in most cases, sweetening compositions of thepresent invention are preferred by test subjects over compositions thatcomprise 97% rebaudioside A, when tested at the same concentration.Adding Stevia extract and sweetening compositions of the presentinvention to foods and beverages is expected to result in better tastingfoods and beverages compared to those prepared with known Steviaextracts and sweetening compositions containing sweet steviolglycosides, such as compositions having 97% rebaudioside A.

It is also contemplated that rebaudioside B may be added to other highintensity sweeteners. Representative examples of high intensitysweeteners suitable for embodiments of the invention include naturalhigh intensity sweeteners such as:

-   -   dulcoside A, dulcoside B (also known as rebaudioside C),        rubusoside, siamenoside, monatin and its salts (monatin SS, RR,        RS, SR), curculin, glycyrrhizic acid and its salts, thaumatin,        monellin, mabinlin, brazzein, hernandulcin, phyllodulcin,        glycyphyllin, phloridzin, stevioside, rebaudioside A,        rebaudioside D, rebaudioside E, rebaudioside F, stevia,        steviolmonosides, and steviolbiosides;        and artificial high intensity sweeteners such as:    -   saccharin, aspartame, sucralose, neotame, acesulfame potassium.        Further, one of skill in the art will recognize that        rebaudioside B can be added to caloric sweeteners, such as        sugars (e.g., high fructose corn syrup, sucrose, fructose, etc.)        and polyols (e.g., sorbitol, xylitol, lactitol, etc.) or other        low-calorie sweeteners to produce sweetening compositions that        are reduced in caloric value.

Simple extraction of steviol glycosides from plants generally results inextracts that are less preferred in terms of taste than purifiedextracts higher in rebaudioside A. However, simple extracts are easierto produce and are generally less expensive to produce than high purityrebaudioside A. Therefore, a further advantage of the present inventionmay be a combination of a simple extract or partially purified productwith rebaudioside B, so as to obtain a glycoside mixture that is lessexpensive to produce than purified rebaudioside A, yet possessescomparable or superior flavor characteristics. It is also contemplatedthat steviol glycoside processing streams that have been depleted ofgood tasting glycosides during the purification of rebaudioside A can bemade to taste better by increasing the rebaudioside B content.

The compositions containing rebaudioside B may be further modified usingknown technology to modify particle size such as agglomeration,spray-drying, drum drying and other forms of physical processingcommonly applied to adjust particle size in order to deliver betterflow, hydration, or dissolution properties.

The compositions containing rebaudioside B may be further modified usingknown technology to provide liquid forms with preservative forease-of-use in specific applications.

The compositions containing rebaudioside B may be further modified usingknown techniques to co-process with bulking agents such as maltodextrinsand similar compounds to deliver products with controlled sweetness,dosing, potency, and handling properties. Further, it is to be notedthat rebaudioside B and/or combinations of it and other steviolglycosides can be combined with other ingredients that may be desirableto include in a sweetening composition. For example, rebaudioside B maybe spray coated or spray agglomerated onto rebaudioside A or othersteviol glycosides and/or with other materials such as maltodextrins,sucrose, or any other desired functional carrier.

III. Stevia Extracts and Sweetening Compositions Comprising RebaudiosideB

It has been discovered that the taste of sweet steviol glycosidemixtures and blends (e.g., steviol glycoside mixtures and blends) can beimproved by controlling and/or increasing the concentrations ofrebaudioside B in steviol glycoside compositions in accordance with thepresent invention. It is believed that the improved taste is evident atpH values from about pH 2 to about pH 8.

The solubility limits of rebaudioside B were determined (see Example 5).For example, experimental results to date indicate that (i) rebaudiosideB has relatively high solubility in neutral pH solution and (ii) thesolubility of rebaudioside B is limited in a pH 3 citric buffer. Furtherexperimental results to date indicate that the presence of rebaudiosideA in solution increases the solubility of rebaudioside B. On the otherhand, experimental results to date indicate that the presence ofstevioside slightly reduces the solubility of rebaudioside B. Thissolubility information may be considered when formulating solutions ofrebaudioside B and mixtures of rebaudiosides.

Rebaudioside B for mixing with other sweeteners can be obtained invarious ways. For example, rebaudioside B can be isolated from plantextracts by chromatography, precipitation, or crystallization.Alternatively, rebaudioside B may be obtained by treating rebaudioside Awith various hydroxides of mono, di, and trivalent cations underappropriate temperature and pH conditions. The rebaudioside B mixturewith residual rebaudioside A can be used to increase the amount ofrebaudioside B in another mixture, or the rebaudioside B can be isolatedfrom the rebaudioside A/rebaudioside B mixture by chromatography,precipitation, or selective crystallization. Rebaudioside B can also beobtained in a similar manner by treating rebaudioside D with the samehydroxide compounds as mentioned above for rebaudioside A. The productmixture or isolated rebaudioside B can be used to prepare the abovementioned improved tasting steviol glycoside mixtures. As anotheralternative, rebaudioside B can be produced enzymatically fromrebaudioside A or rebaudioside D.

In certain embodiments, a Stevia extract or sweetening compositioncomprises rebaudioside B and one or more additional sweet glycosidecompounds. Representative examples of sweet glycoside compounds includerebaudioside A, rebaudioside B, rebaudioside C (dulcoside B),rebaudioside D, rebaudioside E, rebaudioside F, stevia, stevioside,dulcoside A, and rubusoside. In certain embodiments, the one or moresweet glycosides may be sweet steviol glycosides, includingsteviolbiosides and steviolmonosides. More specifically, representativeexamples of sweet steviol glycosides include rebaudioside A,rebaudioside B, rebaudioside C, rebaudioside D, rebaudioside E,rebaudioside F, and stevioside. For example, partially purifiedextractions of steviol glycosides from plants often comprise a mixtureof rebaudioside B and additional steviol glycosides.

In certain embodiments where a Stevia extract or sweetening compositioncomprises rebaudioside B and one or more additional sweet steviolglycoside compounds, the amount of rebaudioside B is at a concentrationthat is at least about 10% by weight of the total amount of sweetsteviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments the rebaudioside B is at aconcentration that is at least about 15% by weight of the total amountof sweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments the rebaudioside B is at aconcentration that is at least about 20% by weight of the total amountof sweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments the rebaudioside B is at aconcentration that is at least about 25% by weight of the total amountof sweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments the rebaudioside B is at aconcentration that is at least about 30% by weight of the total amountof sweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments the rebaudioside B is at aconcentration that is at least about 35% by weight of the total amountof sweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments the rebaudioside B is at aconcentration that is at least about 40% by weight of the total amountof sweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments the rebaudioside B is at aconcentration that is at least about 45% by weight of the total amountof sweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments the rebaudioside B is at aconcentration that is at least about 50% by weight of the total amountof sweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition.

In certain embodiments where a Stevia extract or sweetening compositioncomprises rebaudioside B and one or more additional sweet steviolglycoside compounds and where the concentration of rebaudioside B is ata concentration consistent with any of the embodiments described above(the term “consistent” rules out potential combinations wherein a lowerlimit of a range from above is selected that is greater than an upperlimit of a range from below), the concentration of rebaudioside B mayalso be at a concentration that is not greater than about 90% by weightof the total amount of sweet steviol glycoside compounds in the Steviaextract or sweetening composition. In certain embodiments where theconcentration of rebaudioside B is at a concentration consistent withany of the embodiments described above, the concentration ofrebaudioside B is not greater than about 80% by weight of the totalamount of sweet steviol glycoside compounds in the Stevia extract orsweetening composition. In certain embodiments where the concentrationof rebaudioside B is at a concentration consistent with any of theembodiments described above, the concentration of rebaudioside B is notgreater than about 70% by weight of the total amount of sweet steviolglycoside compounds in the Stevia extract or sweetening composition. Incertain embodiments where the concentration of rebaudioside B is at aconcentration consistent with any of the embodiments described above,the concentration of rebaudioside B is not greater than about 60% byweight of the total amount of sweet steviol glycoside compounds in theStevia extract or sweetening composition. In certain embodiments wherethe concentration of rebaudioside B is at a concentration consistentwith any of the embodiments described above, the concentration ofrebaudioside B is not greater than about 50% by weight of the totalamount of sweet steviol glycoside compounds in the Stevia extract orsweetening composition. In certain embodiments where the concentrationof rebaudioside B is at a concentration consistent with any of theembodiments described above, the concentration of rebaudioside B is notgreater than about 40% by weight of the total amount of sweet steviolglycoside compounds in the Stevia extract or sweetening composition. Incertain embodiments where the concentration of rebaudioside B is at aconcentration consistent with any of the embodiments described above,the concentration of rebaudioside B is not greater than about 35% byweight of the total amount of sweet steviol glycoside compounds in theStevia extract or sweetening composition. In certain embodiments wherethe concentration of rebaudioside B is at a concentration consistentwith any of the embodiments described above, the concentration ofrebaudioside B is not greater than about 30% by weight of the totalamount of sweet steviol glycoside compounds in the Stevia extract orsweetening composition. In certain embodiments where the concentrationof rebaudioside B is at a concentration consistent with any of theembodiments described above, the concentration of rebaudioside B is notgreater than about 25% by weight of the total amount of sweet steviolglycoside compounds in the Stevia extract or sweetening composition.

In certain embodiments, the one or more additional sweet steviolglycoside compound comprises rebaudioside A. For example, partiallypurified extractions of steviol glycosides may comprise a mixture ofrebaudioside B and rebaudioside A or rebaudioside B may be incorporatedinto purified preparations of rebaudioside A. In certain embodimentscomprising rebaudioside A, the amount of rebaudioside A in the Steviaextract or sweetening composition is at a concentration that is at leastabout 1% by weight of the total amount of sweet steviol glycosidecompounds in the Stevia extract or sweetening composition. In certainembodiments the amount of rebaudioside A is at least about 5% by weightof the total amount of sweet steviol glycoside compounds in the Steviaextract or sweetening composition. In certain embodiments the amount ofrebaudioside A is at least about 10% by weight of the total amount ofsweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments the amount of rebaudioside A is atleast about 20% by weight of the total amount of sweet steviol glycosidecompounds in the Stevia extract or sweetening composition. In certainembodiments the amount of rebaudioside A is at least about 30% by weightof the total amount of sweet steviol glycoside compounds in the Steviaextract or sweetening composition. In certain embodiments the amount ofrebaudioside A is at least about 40% by weight of the total amount ofsweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments the amount of rebaudioside A is atleast about 50% by weight of the total amount of sweet steviol glycosidecompounds in the Stevia extract or sweetening composition. In certainembodiments the amount of rebaudioside A is at least about 60% by weightof the total amount of sweet steviol glycoside compounds in the Steviaextract or sweetening composition. In certain embodiments the amount ofrebaudioside A is at least about 70% by weight of the total amount ofsweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition.

In certain embodiments comprising rebaudioside A wherein theconcentration of rebaudioside A is at a concentration consistent withany of the embodiments described above, the rebaudioside A is at aconcentration that is not greater than about 95% by weight of the totalamount of sweet steviol glycoside compounds in the Stevia extract orsweetening composition. In certain embodiments comprising rebaudioside Awhere the concentration of rebaudioside A is at a concentrationconsistent with any of the embodiments described above, the rebaudiosideA is at a concentration that is not greater than about 90% by weight ofthe total amount of sweet steviol glycoside compounds in the Steviaextract or sweetening composition. In certain embodiments comprisingrebaudioside A where the concentration of rebaudioside A is at aconcentration consistent with any of the embodiments described above,the rebaudioside A is at a concentration that is not greater than about85% by weight of the total amount of sweet steviol glycoside compoundsin the Stevia extract or sweetening composition. In certain embodimentscomprising rebaudioside A where the concentration of rebaudioside A isat a concentration consistent with any of the embodiments describedabove, the rebaudioside A is at a concentration that is not greater thanabout 80% by weight of the total amount of sweet steviol glycosidecompounds in the Stevia extract or sweetening composition. In certainembodiments comprising rebaudioside A where the concentration ofrebaudioside A is at a concentration consistent with any of theembodiments described above, the rebaudioside A is at a concentrationthat is not greater than about 75% by weight of the total amount ofsweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments comprising rebaudioside A where theconcentration of rebaudioside A is at a concentration consistent withany of the embodiments described above, the rebaudioside A is at aconcentration that is not greater than about 70% by weight of the totalamount of sweet steviol glycoside compounds in the Stevia extract orsweetening composition. In certain embodiments comprising rebaudioside Awhere the concentration of rebaudioside A is at a concentrationconsistent with any of the embodiments described above, the rebaudiosideA is at a concentration that is not greater than about 65% by weight ofthe total amount of sweet steviol glycoside compounds in the Steviaextract or sweetening composition. In certain embodiments comprisingrebaudioside A where the concentration of rebaudioside A is at aconcentration consistent with any of the embodiments described above,the rebaudioside A is at a concentration that is not greater than about60% by weight of the total amount of sweet steviol glycoside compoundsin the Stevia extract or sweetening composition. In certain embodimentscomprising rebaudioside A where the concentration of rebaudioside A isat a concentration consistent with any of the embodiments describedabove, the rebaudioside A is at a concentration that is not greater thanabout 55% by weight of the total amount of sweet steviol glycosidecompounds in the Stevia extract or sweetening composition. In certainembodiments comprising rebaudioside A where the concentration ofrebaudioside A is at a concentration consistent with any of theembodiments described above, the rebaudioside A is at a concentrationthat is not greater than about 50% by weight of the total amount ofsweet steviol glycoside compounds in the Stevia extract or sweeteningcomposition.

Although sweetening compositions of the invention may comprise mixturesof various types of sweeteners in various quantities, in certainembodiments, a sweetening composition with rebaudioside B and one ormore additional sweet steviol glycoside compounds consists essentiallyof sweet steviol glycoside compounds. For example, in such embodimentsthe total concentration of rebaudioside B and all other sweet steviolglycoside compounds present therein provide essentially all thesweetness functionality of the sweetening composition. The amount ofother sweetening compounds that could be included in sweeteningcompositions that consists essentially rebaudioside and sweet steviolglycoside compounds will depend upon the type of other sweeteningcompound in question and its sweetness threshold concentration belowwhich it is believed it does not appreciably contribute to the sweetnessof a sweetening composition. Further, in certain embodiments, asweetening composition with rebaudioside B and one or more additionalsweet steviol glycoside compounds consists of sweet steviol glycosidecompounds.

In certain embodiments the Stevia extract or sweetening compositioncomprising rebaudioside B and one or more additional sweet steviolglycoside compounds comprises stevioside. In certain embodiments, theconcentration of stevioside is at least about 1% by weight of the totalamount of sweet steviol glycoside compounds in the Stevia extract orsweetening composition. In certain embodiments, the concentration ofstevioside is at least about 5% by weight of the total amount of sweetsteviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments, the concentration of stevioside isat least about 10% by weight of the total amount of sweet steviolglycoside compounds in the Stevia extract or sweetening composition. Incertain embodiments, the concentration of stevioside is at least about20% by weight of the total amount of sweet steviol glycoside compoundsin the Stevia extract or sweetening composition. In certain embodiments,the concentration of stevioside is at least about 30% by weight of thetotal amount of sweet steviol glycoside compounds in the Stevia extractor sweetening composition. In certain embodiments, the concentration ofstevioside is at least about 40% by weight, of the total amount of sweetsteviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments, the concentration of stevioside isnot greater than about 95% by weight of the total amount of sweetsteviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments, the concentration of stevioside isnot greater than about 90% by weight of the total amount of sweetsteviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments, the concentration of stevioside isnot greater than about 80% by weight of the total amount of sweetsteviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments, the concentration of stevioside isnot greater than about 70% by weight of the total amount of sweetsteviol glycoside compounds in the Stevia extract or sweeteningcomposition. In certain embodiments, the concentration of stevioside isnot greater than about 60% by weight of the total amount of sweetsteviol glycoside compounds in the Stevia extract or sweeteningcomposition.

IV. Products Comprising High Rebaudioside B Sweeteners

Certain embodiments of the invention are drawn to foodstuffs comprisingStevia extract or sweetening compositions with high concentrations ofrebaudioside B. One of skill in the art would recognize any edible orchewable compositions may be sweetened in accordance with the presentinventions, such as foodstuffs, (e.g., snacks, baked goods, soups,sauces, processed meats canned fruits, canned vegetables, dairyproducts, frozen confections, cakes, cookies, bars, and other sweetbakery items, cereals, cereal bars, yogurt, yogurt-containing drinks,energy bars, granola bars, hard candy, jelly candy, chocolate candy, andother sweet confections); beverages (e.g., carbonated soft drinks, readyto drink teas, sports drinks, dairy drinks, alcoholic beverages, energydrinks, coffees, flavored waters, vitamin drinks, fruit drinks, andfruit juices, powdered soft drinks), medicines or pharmaceuticalproducts (e.g., tablets, lozenges, suspensions, etc.), nutraceuticalproducts (e.g., supplements, vitamins, etc.), candy or confections;chewing gum; tobacco products (e.g., chewing tobacco); and the like. Theaddition of rebaudioside B or Stevia extracts or sweetening compositionscomprising rebaudioside B and other optional sweeteners to foodstuffs isa process that will depend on the foodstuff and its preparation. Suchpreparation is known to those skilled in the art of preparingfoodstuffs. Preferably, the sweetening composition is included in aneffective amount that imparts the desired amount of sweetness tofoodstuff. One of skill in the art would recognize that it is routinepractice to determine the preferred amount of sweetener to add in thepreparation of foodstuffs.

In certain embodiments, the foodstuff contains a sweetening compositioncomprising rebaudioside B and one or more additional sweet steviolglycoside compounds as described herein. In certain embodiments, steviolglycosides of the sweetening composition are at a total concentrationthat is less than their sweetening threshold (which is believed to beabout 40 ppm). In such an embodiment, it is believed that at such lowamounts the sweet steviol glycosides are functioning as a flavoringagent or a flavor enhancing agent rather than as a sweetener. In certainembodiments, the sweet steviol glycosides of the sweetening compositionare at a total concentration that is at least about 50 ppm. In certainembodiments, the sweet steviol glycosides of the sweetening compositionare at a total concentration that is at least about 200 ppm, or at aconcentration that is at least about 500 ppm, or at a concentration thatis at least about 1500 ppm.

In certain embodiments, the foodstuff is a beverage containing asweetening composition comprising rebaudioside B and one or moreadditional sweet steviol glycoside compounds as described herein. Incertain embodiments, the pH of the beverage is at least about pH 2 (andpreferably at least about pH 4) and not greater than about pH 8. Incertain embodiments, the sweet steviol glycosides of the sweeteningcomposition are at a total concentration that is at least about 50 ppm.In certain embodiments, the sweet steviol glycosides of the sweeteningcomposition are at a total concentration that is at least about 200 ppm,or at least about 500 ppm, or at least about 1500 ppm.

V. Production of Sweetening Composition

Sweetening compositions in accordance with the principles set forthherein may be produced according to any appropriate method of whichthere are a variety. One such method involves blending certain amountsof rebaudioside B with and one or more additional sweet steviolglycoside compounds such as rebaudioside A and/or other sweet steviolglycoside compounds. For example a blend of purified rebaudioside B andrebaudioside A and/or other sweet steviol glycoside compounds may bemade by blending dry powders of the components. Alternatively, a mixtureof sweet steviol glycoside compounds may be prepared in solution orsuspension and co-dried to produce a powder.

Rebaudioside A is a commercially available material that is typicallycharacterized as being, for example, >80% rebaudioside A, >95%rebaudioside A, or ≧97% of rebaudioside A. Such a purified form ofrebaudioside A is typically achieved by reducing the amounts of othersteviol glycosides by using solvent recrystallization, adsorptionresins, or chromatographic fractionation.

Rebaudioside B may be obtained according to a variety of means. Forexample, rebaudioside B may recovered from process streams associatedwith processing and purifying rebaudioside A by using, for example,precipitation, recrystallization, chromatographic fractionation,adsorption resins. Additionally, rebaudioside B may be obtained by thealkaline or acid hydrolysis of rebaudioside A such as disclosed byKohda, et. al., Phytochemistry, vol. 15, pp. 981-983 (1975) andJP52083731A. Rebaudioside B may also be produced by the enzymatichydrolysis of rebaudioside A such as disclosed by Mizukani, H., et al.,Phytochem vol. 21, pp. 1927-1930 (1982).

Because rebaudioside B may be formed from rebaudioside A, steviaextracts may have their rebaudioside B content increased by, forexample, modifying the process parameters associated with the extractionof steviol glycosides from the stevia plant. For example, the amount ofrebaudioside B may be increased by controlling the pH of a processstream, the temperature of a process stream, increasing processduration, or a combination of such modifications.

If desired, rebaudioside B may be separated from other steviolglycosides and related compounds using any appropriate method. Forexample, rebaudioside B may be precipitated from solutions by decreasingthe solution pH. Rebaudioside B is typically transformed into itsessentially insoluble, protonated form in room temperature water at pHvalues lower than about 4.5.

After the precipitation of rebaudioside B, it may be separated from thesolution comprising solute compounds by any of common means of purifyinga suspension. The precipitate can be centrifuged and the supernatantremoved. The precipitate can be separated by filtration such as vacuumfiltration or the use of a filter press. The soluble and insolublephases can be separated by use of membranes. The filter cake, centrifugepellet, or membrane retentate can be further purified by washing withwater. Alternatively, the partially purified and recovered precipitatecan be re-dissolved in water of pH greater than about 7.7,re-precipitated by the addition of acid to drop pH below about 4.5, andagain separated from the impurity-containing liquid phase by any of theabove techniques.

Alternatively, rebaudioside B may be precipitated by the addition of asolvent in which rebaudioside B has limited solubility or is insoluble.The specific solvent, amount added, and temperature are preferably to beselected such that essentially only rebaudioside B precipitates, notother compounds.

At neutral pH in water, soluble rebaudioside B may be separated fromother soluble compounds by chromatographic fractionation,recrystallization, membrane separation using a membrane of appropriatepore size that retains rebaudiosides but allows smaller molecules topass, or treatment with adsorptive resins that will either adsorb allimpurities, eluting rebaudiosides, or adsorb rebaudiosides and elute allimpurities. The resin would then be washed with an eluent havingaffinity for the adsorbed material, to regenerate the resin (in thefirst case) or recover the rebaudiosides (second case).

Separated rebaudioside B may be dried by any appropriate method andassociated apparatus such as by belt drying, drum drying, tray drying,spray drying, freeze drying, flash drying, or drying with a fluidizedbed. Alternatively, instead of drying rebaudioside B and then blendingthe dried rebaudioside B with rebaudioside A and/or other sweetsteviolside compounds, one may blend the same while in solution and thendry the composition.

EXAMPLES

The following disclosed embodiments are merely representative of theinvention which may be embodied in various forms. Thus, specificstructural, functional, and procedural details disclosed in thefollowing examples are not to be interpreted as limiting.

Example 1 Preference Testing of Commercial Mixtures of SteviolGlycosides and Rebaudioside B Enriched Glycoside Mixtures

A commercial blend of a steviol glycosides was dissolved in 0.0056 Mcitric acid buffer pH 3.1. A solution containing a commerciallyavailable sweetening composition containing 97% rebaudioside A wassimilarly prepared.

TABLE 1 97% Rebaudioside A and Commercial Blend Compositions. 97%rebaudioside Commercial Glycoside A, mg blend, mg/l Rebaudioside A 473437 Stevioside 1 35 Rebaudioside B 14 17 Rebaudioside C 0 9 RebaudiosideD 0 20 Total 498 518

Thirty-one Tate & Lyle employees participated in paired comparison testsfor sweetness and preference. The products were made up in pH 3.1 citricacid buffer (0.9 grams anhydrous citric acid (Tate & Lyle, Decatur,Ill.) and 0.26 grams sodium citrate dihydrate (Tate & Lyle, Decatur,Ill.) per liter and tested at room temperature in two ounce soufflé cupslabel with random three-digit codes. The presentation order was rotated.The panelists were asked to identify the solution that was sweeter andwhich they like better. The ballot was presented and the data wascollected with SIMS sensory software (Sensory Computer Systems, LLC,Morristown, N.J.). Bottled water, a 2% sucrose solution, and unsaltedcrackers were available for the panelists to clear their palates beforeand during testing.

The results of the sweetness and preference questions were analyzed withthe binomial test and the Thurstonian d′ calculated. The p-value for aone-tailed binomial test is calculated as

$1 - {\sum\limits_{k = 0}^{c}{\begin{pmatrix}n \\k\end{pmatrix}{p_{0}^{k}\left( {1 - p_{0}} \right)}^{n - k}}}$where c is the number of successes, n is the number of trials, and p₀ isthe chance probability. A test is considered statistically significantwhen the p-value is less than the a priori set alpha risk. Thetwo-tailed p-value is double the one-tailed p-value as calculated above.

Thurstonian d′ is a linear measure of psychophysical difference. A d′ of1 is generally considered to be a just-noticeable-difference (JND) wherea stimulus will be judge stronger in 75% of the trials. The Thurstoniand′ is independent of test method and for paired comparison tests iscalculated asp _(c)=Φ(d′/√{square root over (2)})where p_(c) is the proportion of successes, and Φ(•) is the cumulativedistribution function of the standard normal distribution. Thesestatistical terms are more fully defined in standard textbooks on thesubject such as “Sensory Discrimination Tests and Measurements”, Jian Bi(Blackwell Publishing, 2006).

The instructions for the paired comparison test were:

-   -   (i) It is important that you rinse before and between samples.    -   (ii) Clear your palate with a bite of cracker. Then rinse with        the sugar water. Finally rinse with plain water.    -   (iii) Taste the samples in the order presented, from left to        right.    -   (iv) Taste at least half of the first sample and note the        sweetness.    -   (v) Rinse with the sugar water followed by rinsing with plain        water.    -   (vi) Now taste at least half of the second sample.    -   (vii) Do not re-taste the first sample.    -   (viii) Evaluate the samples for preference and sweetness. Pick        the sample that you like more and pick the sample that is        sweeter. They may or may not be the same sample. If you are not        sure or don't have a preference then pick either one.        The questions for the paired comparison test were:    -   (i) Which of these two samples do you like more?    -   (ii) Which of the two samples is sweeter?

The results of this test and the psychophysical d′ value are shown inTable 2 below.

TABLE 2 Commercial Blend vs. 97% rebaudioside A Sample # preferring #sweeter Commercial Blend 11 16 97% rebaudioside A 20 15 Totals 31 31Binomial p-value, 0.07 0.72 two tailed d′ value −0.53 0.16The results show that the commercial blend was found to be slightly lesspreferred and about as sweet as the 97% rebaudioside A.

In a subsequent test performed the same way, an addition of rebaudiosideB was made to the foregoing Commercial Blend to make a mixture ofglycosides that is an embodiment of the present invention having aconcentration of rebaudioside B relative to the total amount of sweetsteviol glycosides of about 21% and a ratio of rebaudioside A torebaudioside B of about 3:1.

The glycoside blend of a steviol glycosides was dissolved in 0.0056 Mcitric acid buffer pH 3.1. A solution containing a commerciallyavailable sweetening composition containing 97% rebaudioside A wassimilarly prepared.

TABLE 3 97% rebaudioside A and Glycoside Mixture Compositions. 97%rebaudioside Mixture, Glycoside A, mg mg/l Rebaudioside A 473 350Stevioside 1 32 Rebaudioside B 14 104 Rebaudioside C 0 10 Rebaudioside D0 0 Total 498 496

The two solutions were presented to a panel of Tate & Lyle employees andthey were asked to identify the solution that was sweeter and which theylike better using the same instructions and questions as set forthabove. The results of the sweetness and preference questions wereanalyzed with the binomial test and the Thurstonian d′ calculated as setforth above. The results and the psychophysical d′ value are presentedin Table 4 below.

TABLE 4 Rebaudioside B blend vs. 97% Rebaudioside A Sample # preferring# sweeter Rebaudioside B blend 27 27 97% rebaudioside A 11 11 Totals 3838 Binomial p-value, <0.01 <0.01 two tailed d′ value 0.79 0.79The rebaudioside B blend was both preferred and found to be sweeter than97% rebaudioside A.

Example 2 Preference Testing of 800 ppm Mixtures of Rebaudioside A or BMixed with Stevioside

A taste panel was asked to compare a commercial mixture of rebaudiosideA and stevioside to a 500 ppm sample of 97% rebaudioside A. Theglycoside blend of steviol glycosides was dissolved in 0.0056 M citricacid buffer pH 3.1. A solution containing a commercially availablesweetening composition containing 97% rebaudioside A was similarlyprepared. Sample presentation was rotated and the samples of the twosolutions (at room temperature) were presented to a panel of Tate & Lyleemployees and they were asked to identify the solution that was sweeterand which they like better using the same instructions and questions asin Example 1. The results of the sweetness and preference questions wereanalyzed with the binomial test and the Thurstonian d′ calculated as inExample 1.

TABLE 5 97% Rebaudioside A and Rebaudioside A and Stevioside MixtureCompositions. 97% rebaudioside Mixture, Glycoside A, mg mg/lRebaudioside A 473 374 Stevioside 1 403 Rebaudioside B 14 11Rebaudioside C 0 0 Rebaudioside D 0 0 Total 498 789

Another panel was asked to compare a mixture of rebaudioside B andStevioside. The glycoside blend of steviol glycosides was dissolved in0.0056 M citric acid buffer pH 3.1. A solution containing a commerciallyavailable sweetening composition containing 97% rebaudioside A wassimilarly prepared. The two solutions were presented to a panel of Tate& Lyle employees and they were asked to identify the solution that wassweeter and which they like better using the same instructions andquestions as in Example 1.

TABLE 6 97% Rebaudioside A and Rebaudioside B and Stevioside MixtureCompositions. 97% rebaudioside Mixture, Glycoside A, mg mg/lRebaudioside A 473 4 Stevioside 1 397 Rebaudioside B 14 400 RebaudiosideC 0 0 Rebaudioside D 0 0 Total 498 801

The results of the sweetness and preference questions were analyzed withthe binomial test and the Thurstonian d′ calculated as in Example 1. Theresults of the two panels and the psychophysical d′ values are shown inTable 7 and Table 8 respectively.

TABLE 7 Rebaudioside A & stevioside blend vs. 97% Rebaudioside A Sample# preferring # sweeter Rebaudioside A and 4 22 stevioside 97%rebaudioside A 37 19 Totals 41 41 Binomial p-value, <0.01 0.27 twotailed d′ value −1.83 0.13The results show that the rebaudioside A—stevioside blend was much lesspreferred as compared to 97% rebaudioside A and was found to be nearlyequally sweet.

TABLE 8 Rebaudioside B & stevioside blend vs. 97% Rebaudioside A Sample# preferring # sweeter rebaudioside B and 21 30 stevioside 97%rebaudioside A 22 13 Binomial p-value, 0.38 <0.01 two tailed Totals 4343 d′ value −0.04 0.73The results show that the rebaudioside B—stevioside blend was equallypreferred to the 97% rebaudioside A (500 ppm) and the rebaudiosideB—stevioside blend found to be sweeter than the 97% rebaudioside A.

Example 3 Preference Testing Mixtures of Rebaudioside A or B

A taste panel was asked to compare a commercial mixture of rebaudiosideA and rebaudioside B and a 900 ppm sample of 97% rebaudioside A. Tate &Lyle employees participated in paired comparison tests for sweetness andpreference. Samples were tested at room temperature in two ounce soufflécups label with random three-digit codes. The presentation order was notrotated because of carryover of the off-flavor of rebaudioside A at 900ppm. The panelist evaluated the test sample first and then the control900 ppm rebaudioside A sample. The panelists were instructed not tore-taste the samples. Additionally, the panelists were required to waitone minute between testing samples and instructed to clear their palateswith a 2% sucrose solution, an unsalted cracker, and bottled water. Thepanelists were asked to identify the solution that was sweeter and whichthey like better. The ballot was presented and the data was collectedwith SIMS sensory software (Sensory Computer Systems, LLC, Morristown,N.J.).

TABLE 9 97% Rebaudioside A and Rebaudioside A and Rebaudioside B MixtureCompositions. Ingredient Test Control Hinkley Spring Water 98.88 98.88Rebaudioside A 0.0536 0.0900 Rebaudioside B 0.0310 0.0000 PhosphoricAcid, 85% 0.0361 0.0361 Total 100 100

The instructions for the paired comparison test were:

-   -   (i) It is important that you rinse before and between samples.    -   (ii) Clear your palate with a bite of cracker. Then rinse with        the sugar water. Finally rinse with plain water.    -   (iii) Taste the samples in the order presented, from left to        right.    -   (iv) Taste at least half of each sample and note the sweetness.    -   (v) Rinse with the sugar water followed by rinsing with plain        water.    -   (vi) Evaluate the samples for preference and sweetness. Pick the        sample that you like more and pick the sample that is sweeter.        They may or may not be the same sample. If you are not sure or        don't have a preference then pick either one.    -   (vii) Taste the sample on the left now.    -   (viii) Wait one minute before tasting the next sample (60 second        timer started in SIMS)    -   (ix) Taste the sample on the right now.        The questions for the paired comparison test were:    -   (i) Which of these two samples do you like more? Carefully check        the 3-digit code before marking your answer. They may not appear        in the same order as the samples were presented.    -   (ii) Which of the two samples is sweeter?        (120 second timer started in SIMS between tests). The results of        the sweetness and preference questions were analyzed with the        binomial test and the Thurstonian d′ calculated as in Example 1.

The results of the two panels and the psychophysical d′ values are shownin Table 11.

TABLE 11 Rebaudioside A & Rebaudioside B vs. 97% Rebaudioside A p-valuep-value two- one- sweetness tailed d′ preference tailed d′ Test 1 536ppm 23 0.14 0.38 36 <0.01 2.29 Reb A 310 ppm Reb B control 15 2 900 ppmReb AThe results show that the rebaudioside A—Rebaudioside B blend waspreferred as compared to 97% rebaudioside A and was found to be nearlyequally sweet.

Example 4 Preference Testing of Mixtures of Steviol Glycosides

This study was performed to determine the preference for blends ofrebaudioside A and rebaudioside B relative to rebaudioside A alone at asweetness of approximately 10 SEV with the sensory methodology changedto reduce panelist confusion with the ballot and requiring the panelisttesters to consume approximately 2 ounces of each sample.

Panelists were used in paired comparison tests for sweetness andpreference. The products were tested at refrigerated temperature in twoounce soufflé cups label with three-digit codes. The samples were pouredimmediately before serving. The panelists were asked to identify thebeverage that is sweeter and which they like better. Bottled water, a 2%sucrose solution, and unsalted crackers were available for the paneliststo clear their palates before and during testing.

The panelists evaluated the test sample first and then evaluated thecontrol 900 ppm rebaudioside A sample second. The presentation order inthis test was not rotated because of carryover of the off-flavor ofrebaudioside A at 900 ppm. The panelists were instructed to consume allof the samples and not to re-taste the samples. The panelists werealerted to the fact that the order of the samples on the ballot may notbe the same as the order the samples are presented. The panelists wereinstructed to mark the sample they prefer with an adhesive-backed noteand these results were compared to the results from the ballot. Therewas an enforced rest of one minute between samples and two minutesbetween tests where the panelists were instructed to clear their palateswith 2% sucrose, cracker, and water.

The products tested were lemon-lime carbonated soft drinks comprisingone part syrup and four parts carbonated water, wherein the syrups hadthe compositions set forth in Table 12, below.

TABLE 12 Syrup Formulations Ingredient Test 1 Control Hinkley SpringWater 98.20 98.18 Sodium Benzoate 0.10 0.10 REB A 0.268 0.450 REB B0.155 0.000 Sodium Citrate Dihydrate 0.15 0.15 Citric Acid Anhydrous0.63 0.63 Givaudan Natural Lemon 0.50 0.50 Flavor #881337 Total 100 100

The results were analyzed with the binomial test at an alpha risk of0.05 as a one-tailed test for preference and two-tailed test forsweetness. The results of the test are set forth in Table 13, below.

TABLE 13 Test 1 Beverage compared Control Beverage p-value p-value two-one- sweetness tailed d′ preference tailed d′ Test 1 536 ppm 20 0.76−0.04 26 0.03 0.48 RebA 310 ppm RebB control 21 15 900 ppm RebA

The tests show that both of the test lemon-lime carbonated soft drinksdid not significantly different in sweetness from the rebaudioside Asweetened lemon-lime carbonated soft drink and that they weresignificantly preferred to the rebaudioside A sweetened lemon-limecarbonated soft drink.

The analysis suggests that a blend of rebaudioside A and rebaudioside Bshould be more pleasant than rebaudioside A alone especially at highersweetness levels.

Example 5 Solubility

To determine the solubility of rebaudioside A and rebaudioside B incertain solutions, four stock solutions were prepared. A 10×concentrated citric acid/sodium citrate pH 3 stock buffer solution wasprepared by dissolving 0.9 g anhydrous citric acid and 0.26 g of sodiumcitrate dihydrate in water to make 100 mL of buffer (0.047 M citricacid+0.0088 M sodium citrate). A 2500 ppm (nominal) solution ofrebaudioside A was prepared by dissolving 0.125 g of GLG RA 97 to make50 mL of solution. A 2500 ppm (nominal) solution of stevioside wasprepared by dissolving 0.125 g of GLG STV 97 to make 50 mL of solution.A 1000 ppm (nominal) solution of rebaudioside B was prepared by diluting56 mL of a solution assayed at 1790 ppm to make 100 mL of solution.

These solutions were mixed as 1 mL total amounts by micropipetting thevolumes, in microliters, into 1.5 mL microcentrifuge tubes As shown inTable 14. The resulting nominal concentrations of each of the threeglycosides, in ppm, are also listed in Table 14.

TABLE 14 Summary of Test Solutions Microliters of stock solution added10X 2500 ppm 2500 ppm 1000 ppm PPM (nominal) Tube citric acid Water RebA stevioside Reb B Reb A stevioside Reb B 1 100 200 0 200 500 0 500 5002 100 250 0 150 500 0 375 500 3 100 300 0 100 500 0 250 500 4 100 350 050 500 0 125 500 5 100 400 0 0 500 0 0 500 6 100 150 50 200 500 125 500500 7 100 200 50 150 500 125 375 500 8 100 250 50 100 500 125 250 500 9100 300 50 50 500 125 125 500 10 100 350 50 0 500 125 0 500 11 100 100100 200 500 250 500 500 12 100 150 100 150 500 250 375 500 13 100 200100 100 500 250 250 500 14 100 250 100 50 500 250 125 500 15 100 300 1000 500 250 0 500 16 100 50 150 200 500 375 500 500 17 100 100 150 150 500375 375 500 18 100 150 150 100 500 375 250 500 19 100 200 150 50 500 375125 500 20 100 250 150 0 500 375 0 500 21 100 0 200 200 500 500 500 50022 100 50 200 150 500 500 375 500 23 100 100 200 100 500 500 250 500 24100 150 200 50 500 500 125 500 25 100 200 200 0 500 500 0 500Immediately after mixing, all of the solutions were clear (vs. cloudy)and showed no precipitation. The tubes were then allowed to standundisturbed at room temperature in the lab (˜25° C.) for around 100hours, by which time all of them showed at least some precipitation.After standing for five days (˜100 hours), the tubes were spun in abench top microcentrifuge to pelletize the precipitate. The clearsupernate was sampled into vials and assayed for glycosides using areverse phase high performance liquid chromatograph (HPLC) gradientmethod with UV detection (Waters 2695 Separations Module equipped with aWaters 2487 Dual λ Absorbance Detector or equivalent instrumentation)that is summarized in Table 15. The HPLC conditions were as follows:

-   -   column—Waters Atlantis T3 4.6×250 mm; 4μ with a Phenomenex        Security Guard AQ C18 guard cartridge, 4×3.0 mm;    -   buffer—0.0284% ammonium acetate; 0.0116% acetic acid;    -   flow rate—1.0 mL/min;    -   detector—UV Detector with analysis at 203 nm;    -   inj. vol.—20 μL or as desired to conform to standard        concentration; and    -   col. temp.—40° C.

TABLE 15 HPLC Gradient Method: Mobile Phase: Acetonitrile/Buffergradient Time (min) % Water % Buffer Waters Curve 0 70 30 na 15 65 35 620 65 35 6 25 20 80 6 30 20 80 1 35 70 30 1

The supernatant data collected from the HPLC were processed using DESIGNEXPERT 8 software. Briefly, the data were entered into the program as“factor” data as a 2 factor-5 level general factorial design as thenominal data which were then converted to numerical data and replaced bythe actual HPLC results. The software then selected a model thatpredicted the concentration (solubility) of rebaudioside B as a functionof the concentration of rebaudioside A and stevioside in thesupernatant. The software also calculated a number of statisticalfactors that indicated the significance of the model parameters. In thiscase, the modeling indicated that models with and without a smallrebaudioside A—stevioside interaction parameter were about equally validso we selected the simpler (non-interacting) model for furtherprocessing. The analysis of variance (ANOVA) for this model obtainedfrom the program is shown in Table 16.

TABLE 16 ANOVA Results - Design Expert Response 1 Reb B ANOVA forResponse Surface Linear Model Analysis of variance table [Partial sum ofsquares - Type III] Sum of Mean F p-value Source Squares df Square ValueProb > F Model 61253.89 2 30626.95 443.84 <0.0001 A—Reb A 61056.01 161056.01 884.81 <0.0001 B—Stevioside 363.55 1 363.55 5.27 0.0316Residual 1518.11 22 69.00 Cor total 62772.00 24 Std. Dev. 8.31 R-Squared0.9758 Mean 301.80 Adj R-Squared 0.9736 C.V. % 2.75 Pred R-Squared0.9691 PRESS 1939.25 Adeq Precision 52.665 Coefficient Standard 95% CI95% CI Factor Estimate df Error Low High VIF Intercept 297.61 1 1.67294.15 301.08 A—Reb A 78.09 1 2.63 72.65 83.54 1.00 B—Stevioside −5.66 12.47 −10.78 −0.55 1.00 Final Equation in Terms of Coded Factors: Reb B =+297.61 + 78.09 * A − 5.66 * B Final Equation in Terms of ActualFactors: Reb B = +225.17918 + 0.31238 * Reb A − 0.02264 * Stevioside

Table 17 shows the experimentally determined compositions of thesupernatants from each of the test solutions.

TABLE 17 Raw Assay Data from the HPLC Assayed glycoside concentrationsby HPLC ppm Tube Reb A stevioside Reb B steviolbioside 1 38.8 478 2344.39 2 38.5 351 231 3.61 3 37.6 241 229 2.28 4 36.2 112 233 1.59 5 34.90 226 0.73 6 154 480 265 5.03 7 154 360 255 3.35 8 151 241 284 2.86 9149 121 273 2.03 10 146 0 271 0.77 11 274 476 300 5.1 12 273 363 2934.51 13 269 248 305 3.38 14 260 119 286 1.49 15 260 0 308 0 16 375 473336 4.87 17 381 357 344 3.78 18 372 245 340 2.61 19 370 125 342 2 20 3650 342 0 21 487 475 361 4.74 22 477 356 363 4.35 23 481 245 358 2.72 24498 120 375 1.25 25 484 0 391 0

The rebaudioside B used in this study contained about 6-7% rebaudiosideA which explains the rebaudioside A found in tubes 1-5. It is alsoevident from the data that the concentrations of stevioside andrebaudioside A in the samples are consistent with the belief that thesecompounds are completely soluble in this buffer at this concentration,i.e., only the rebaudioside B was precipitating in the experiment. Thedata shown in Table 17 were entered into DESIGN EXPERT 8 and a twofactor linear regression model was generated, which is set forth inEquation 1, below.ConcB=225.18+0.312*concA−0.02264*concSs  (Eq. 1)The equation shows that the concentration of B in the supernatant(concB, i.e., the solubility limit) was found to be influenced by boththe concentration of rebaudioside A (concA) and the concentration ofstevioside (concSs). The rebaudioside B solubility was increasedsubstantially by increases in the concentration of rebaudioside A, andslightly decreased by the increases in the concentration of stevioside.

The linear-linear model represented by Equation 1 plots as a plane in a3-D plot as shown in FIG. 1. The plane represents the maximum solubilityof rebaudioside B in citric acid buffer (pH 3.1), ranging from a low ofabout 225 ppm when in 478 ppm stevioside (according to the model) toabout 380 ppm in 480 ppm rebaudioside A.

Using the solubility limit (Equation 1) and the constraint that the sumof the mass fractions must add to 1 allows one to find an equation thatrelates the mass fraction of rebaudioside B (X_(B)) at the solubilitylimit to the mass fraction of rebaudioside A (X_(A)), the totalrebaudioside concentration (rebaudioside B+rebaudiosideA+stevioside=C_(tot)), and the coefficients (α₀=225.18 ppm, α₁=0.312,α₂=−0.0226) of the regression equation (Equation 2, below).

$\begin{matrix}{X_{B} = {\frac{\left\lbrack {\frac{\alpha_{0}}{C_{tot}} + \alpha_{2}} \right\rbrack}{\left( {1 + \alpha_{2}} \right)} + {\left\lbrack \frac{\alpha_{1} - \alpha_{2}}{1 + \alpha_{2}} \right\rbrack X_{A}}}} & \left( {{eq}.\mspace{14mu} 2} \right)\end{matrix}$It is believe that Equation 2, therefore, defines the edge of the stablesolution solubility region in ternary mixtures of rebaudioside A,stevioside, and rebaudioside B. Thus, the size of the stable region ableregion will depend on the total concentration (C_(tot)).

This study clearly shows that the solubility of rebaudioside B islimited in pH 3 citric buffer, even though rebaudioside B has highsolubility in neutral pH solutions. In addition the presence ofrebaudioside A increases the solubility of rebaudioside B, but thepresence of stevioside slightly reduces the solubility of rebaudiosideB. This solubility information should be noted when attempting toformulate solutions of rebaudioside B and mixtures of rebaudiosides.

Example 6 Evaluation of Sweetener Taste as a Function of Rebaudioside BContent

A descriptive panel was used to quantify flavor attributes andintensities of varying levels of rebaudioside B added to rebaudioside A(which was 97% pure and contained 0.62% rebaudioside B). Specifically,the sweeteners were evaluated by the panelists at 900 ppm rebaudiosideA+rebaudioside B solutions, wherein the amount of added rebaudioside Bwas such that the total content of rebaudioside B was 0.6%, 3.6%, 6.5%,11.4%, 22.3%, 37.5%, and 52%. An 8% sucrose solution as a control. Thesolutions were prepared in neutral pH water. Other high intensitysweeteners included in the testing were Aspartame at 500 ppm, ASK at 750ppm, Sucralose at 250 ppm, and Stevia at 500 ppm.

Before conducting the testing the ten panelists were extensively trainedin the use of standardized vocabulary to describe the appearance, aroma,flavor, and texture of a wide variety of products in order to rate thesamples for sweetness, bitterness, off flavor, chemical or artificialsweetener flavor, anise, and mouth coating. Each such attribute wasevaluated on a first and second sip, and on after-taste. The testingbegan with a session to orient the panelists during which they tastedthe samples and discussed the flavor characteristics. They also tastedand discussed references for “sweet”, “bitter”, and “anise”. Thedefinitions of flavor terms are set forth in Table 18 below.

TABLE 18 Definitions Term Definition Total Flavor The total intensity ofall the aromas or flavors in the product. Sweet One of the four basictastes, perceived primarily on the tip of the tongue; common to sucroseand other sugars. Total Off All of the flavors of the sample that arenot sweet and Flavor would be considered unintended in the sample.Artificial The flavor reminiscent of artificial sweeteners or Sweetener/chemical tastes not intended to be in foods and Chemical beverages inthe sample. True Bitter One of the four basic tastes, perceivedprimarily on the back of the tongue; common to caffeine and quinine.Anise The total flavor reminiscent of anise or licorice. MouthcoatingThe feeling of any type of coating on the soft tissues of the mouth.During the second and third days of testing, the panelists evaluated thesamples for the various attributes and rated them on a scale from noneto extreme that encompasses all food ingredient products, not justsweeteners. The products and solutions set forth in Table 19 were usedto “anchor” the panelist to the scales.

TABLE 19 Flavor Anchors Flavor Scale Value Reference Anise NR Anise onblotter Sweet 5.0 5% Sucrose in Water 10.0 10% Sucrose in Water Bitter2.0 0.025% Caffeine in Water 5.0 0.04% Caffeine in Water

Eight samples were evaluated per session. A 7 minute rest break wasgiven between each sample and a 15 minute break was given after thefirst 4 samples had been evaluated. Two evaluations (i.e. replicates)were obtained from each panelist for each product; therefore, a total of20 judgments were obtained for each product. During data collection, thepanelists were instructed to indicate the intensity of each sensorycharacteristic by placing a vertical slash on 15-cm line scales. Theserving order was balanced, with products seen approximately an equalnumber of times in each possible position. In the waiting room, ambientAlhambra drinking water, unsalted soda crackers, and celery wereprovided for cleansing the palate between samples.

Slash marks on the line scales were converted to numbers ranging from 1to 15 by SIMS, the computerized sensory data collection system. Meanintensities were calculated for each sensory characteristic. Analysis ofVariance and Duncan's Multiple Range Test, where appropriate, were usedto determine significant differences among the samples for eachattribute. When panelist-by-product interactions were significant, themean square of the interaction term, instead of the mean square of theerror term, was used in calculation of the product F values. The resultsare set forth in Tables 20 and 21, below.

TABLE 20 QUANTITATIVE DESCRIPTIVE EVALUATIONS OF BITTER MASKERS n = 18(9 Panelists, 2 Evaluations Each) 0.6% 3.6% 6.5% 11.4% 22.3% 37.5% 52%P- Conf. Sucrose Reb B Reb B Reb B Reb B Reb B Reb B Reb B Value LevelTOTAL FLAVOR: First Sip d abc a ab bc bc abc c 8.67 9.94 10.16  10.04 9.69 9.61 9.76 9.47 0.0008 ** Second Sip c ab a ab bc c c c 7.86 8.628.79 8.56 8.28 8.07 8.00 7.97 0.0047 ** Aftertaste d ab a bc bc bc c bc4.32 5.96 6.34 5.77 5.59 5.80 5.45 5.63 0.0001 ** SWEET: First Sip d abcab a abc bc abc c 8.06 9.15 9.34 9.56 9.13 9.01 9.21 8.80 0.0057 **Second Sip 7.43 7.27 7.66 7.36 7.40 6.92 6.91 7.02 0.2088 NSD Aftertastec bc a ab ab ab ab ab 3.92 4.44 5.15 4.70 4.58 5.01 4.61 4.75 0.0184 **TOTAL OFF FLAVOR: First Sip e ab a abc cd cd bcd d 0.89 7.69 7.79 7.346.83 6.72 6.98 6.48 0.0001 ** Second Sip c a a a b b b b 0.49 7.01 7.026.88 6.09 5.67 5.83 5.68 0.0001 ** ARTIFICIAL SWEETENER/ CHEMICAL: FirstSip d a ab ab c c bc c 0.59 7.74 7.45 7.37 6.67 6.54 6.87 6.52 0.0001 **Second Sip c a a a b b b b 0.41 6.79 6.88 6.71 5.73 5.31 5.48 5.640.0001 ** Aftertaste f ab a bc cd de e de 0.12 5.00 5.22 4.66 4.39 3.993.79 3.91 0.0001 ** Analysis of Variance Confidence Levels: * = 90%, **= 95% NSD: Not significantly different at confidence levels of 90% orhigher. Mean ratings with different superscripts differ significantly atthe 90% confidence level (Duncan's Multiple Range Test).

TABLE 21 QUANTITATIVE DESCRIPTIVE EVALUATIONS OF BITTER MASKERS(continued) n = 18 (9 Panelists, 2 Evaluations Each) 0.6% 3.6% 6.5%11.4% 22.3% 37.5% 52% P- Conf. Sucrose Reb B Reb B Reb B Reb B Reb B RebB Reb B Value Level TRUE BITTER: First Sip e a ab abc ab cd be d 0.293.78 3.63 3.28 3.37 2.80 3.11 2.49 0.0001 ** Second Sip d a ab ab b c cc 0.24 3.89 3.71 3.46 3.36 2.81 2.62 2.74 0.0001 ** Aftertaste e a a bbc bcd cd d 0.15 3.39 3.45 2.78 2.57 2.26 2.08 1.89 0.0001 ** ANISE:First Sip c ab ab ab a ab ab b 0.52 1.73 1.73 1.45 1.79 1.59 1.58 1.340.0001 ** Second Sip b a a a a a a a 0.41 1.53 1.64 1.36 1.62 1.34 1.361.29 0.0001 ** Aftertaste d a a abc ab c abc bc 0.13 1.42 1.46 1.27 1.340.98 1.12 1.03 0.0001 ** MOUTH- COATING: First Sip c b b b a b b b 0.761.47 1.48 1.40 1.74 1.49 1.49 1.37 0.0001 ** Second Sip b a a a a a a a0.69 1.48 1.46 1.29 1.56 1.42 1.40 1.42 0.0001 ** Analysis of VarianceConfidence Levels: * = 90%, ** = 95% NSD: Not significantly different atconfidence levels of 90% or higher. Mean ratings with differentsuperscripts differ significantly at the 90% confidence level (Duncan'sMultiple Range Test).

FIG. 3 shows the magnitude of the mean responses of the panelists ofeach flavor attribute for which statistically significant differenceswere measured as a function of rebaudioside B content. Because the scaleused encompasses “the universe”, the magnitude of differences betweenthe 97% rebaudioside A solution and increasing levels of rebaudioside Bis not as large as other informal testing determined. For example,several informal testers believed that adding about 20% rebaudioside Areduced the bitterness by about 80% whereas the results fromabove-described panel of tasters showed that adding about 20%rebaudioside A reduced bitterness by about 30%.

The flavor attributes were also compared between the samples. Anattribute is mentioned as ‘highest’ or ‘lowest’ if the sample'sattribute was significantly higher or lower than all of the othersamples. An attribute is mentioned as ‘high’ or ‘low’ if the sample'sattribute was the highest or lowest, respectively, but not significantlyhigher or lower than all of the other samples. Attributes discussedherein were found to be significant at the 95% confidence level.

Compared to the high intensity sweetener samples, sucrose was the Lowestin the following: Total Flavor (although not significantly on the secondsip vs. 22.3%, 37.5%, and 52% rebaudioside B); Sweetness on the firstsip and in the aftertaste (although not significantly lower than thebitter control); Total Off Flavor; Artificial Sweetener/Chemical; TrueBitter; Anise; and Mouthcoating.

Among the high intensity sweetener samples the 97% rebaudioside with0.6% rebaudioside B was High in the following: Total Off Flavor on thesecond sip; Artificial Sweetener/Chemical on the first and second sips;True Bitter; and Anise in the aftertaste.

Among the high intensity sweeteners samples, the sample with 3.6% ofrebaudioside B added was High in the following: Total Flavor; Sweetnessin the aftertaste; Total Off Flavor; Artificial Sweetener/Chemical onthe second sip and in the aftertaste; True Bitter in the aftertaste; andAnise in the aftertaste.

Among the high intensity sweeteners samples, the sample with 6.5% ofrebaudioside B added was High in the following: Sweetness in the firstsip; Total Off Flavor on the second sip; and ArtificialSweetener/Chemical on the second sip.

Among the high intensity sweeteners samples, the sample with 11.4% ofrebaudioside B added was Low in Total Off Flavor on the second sip andArtificial Sweetener/Chemical on the first and second sips and High inAnise on the first sip and Mouthcoating on the first sip.

Among the high intensity sweeteners samples, the sample with 22.3% ofrebaudioside B added was Low in the following: Total Flavor on thesecond sip Total; Total Off Flavor on the second sip; ArtificialSweetener/Chemical on the first and second sips; True Bitter on thesecond sip; and Anise in the aftertaste.

Among the high intensity sweeteners samples, the sample with 37.5% ofrebaudioside B added was Low in the following: Total Flavor on thesecond sip and in the aftertaste; Total Off Flavor on the second sip;Artificial Sweetener/Chemical on the second sip and in the aftertaste;and True Bitter on the second sip.

Among the high intensity sweeteners samples, the sample with 52% ofrebaudioside B added was Low in the following: Total Flavor on the firstand second sips; Sweet on the first sip; Total Off Flavor on the firstand sips; Artificial Sweetener/Chemical on the first and second sips;True Bitter; and Anise on the first sip.

The results indicate that the addition of 3.6% of rebaudioside Bresulted in worse flavor attributes and the addition of 6.5% ofrebaudioside B had little impact on the Total Off Flavor and ArtificialSweetener/Chemical Flavor. The addition of greater amounts ofrebaudioside B tended to result in the samples scoring more closely tosucrose in most characteristics with decreasing off flavors,particularly bitterness. That said, the results show that the increasesthe rebaudioside B content above about 20% had little further impact onundesirable flavor attributes. Surprisingly, the sweetness remainedfairly unaffected by the rebaudioside B content, which is contrary toprevious reports regarding rebaudioside B that found it to be one-halfto two-thirds as sweet as rebaudioside A. Although the Sweetness andTotal Flavor of the high intensity sweetener solutions were similar tothe 8% sucrose solution, and similar to each other, the ArtificialSweetener/Chemical tastes were much higher than the sucrose solution,with a greater spread among high intensity sweetener samples, whichindicates that the rebaudioside B concentration had a significant impacton these tastes.

Advantageously, the present invention may be used to produce highintensity sweetener compositions that can be used to provide the “full”sweetness needed for many applications, which typically cannot beachieved with rebaudioside A alone because of its bitterness atconcentrations above about 200 ppm. More specifically, because thepresent invention allows for the production of high intensity sweetenersthat may be added to consumables such that the consumables comprisesabout 800 to about 1000 ppm of rebaudiosides without the consumablehaving unacceptable levels of bitterness, sweetener compositions of thepresent invention may be used to provide the entire sweetness needed formany consumables (food applications).

What is claimed is:
 1. A sweetening composition comprising sweet steviolglycoside compounds, wherein the sweet steviol glycoside compoundscomprise rebaudioside B at a concentration that is in the range of 10%to about 60% by weight of the total amount of sweet steviol glycosidecompounds in the sweetening composition and rebaudioside A at aconcentration that is in the range of about 40% to about 90% by weightof the total amount of sweet steviol glycoside compounds in thesweetening composition.
 2. The sweetening composition of claim 1,wherein the concentration of the rebaudioside B is in the range of about10% to about 40% by weight of the total amount of sweet steviolglycoside compounds in the sweetening composition.
 3. The sweeteningcomposition of claim 1, wherein the rebaudioside B is at a concentrationthat is at least about 15% and no greater than about 30% by weight ofthe total amount of sweet steviol glycoside compounds in the sweeteningcomposition.
 4. The sweetening composition of claim 1, wherein therebaudioside B is at a concentration that is at least about 20% and nogreater than about 25% by weight of the total amount of sweet steviolglycoside compounds in the sweetening composition.
 5. A consumablecomprising a sweetening composition that comprises sweet steviolglycoside compounds, wherein the sweet steviol glycoside compoundscomprise rebaudioside B at a concentration that is in the range of 10%to about 60% by weight of the total amount of sweet steviol glycosidecompounds in the sweetening composition and rebaudioside A at aconcentration that is in the range of about 40% to about 90% by weightof the total amount of sweet steviol glycoside compounds in thesweetening composition.
 6. The consumable of claim 5, wherein the sweetsteviol glycosides are at a total concentration that is less than theirsweetening threshold.
 7. The consumable of claim 5, wherein the sweetsteviol glycosides are at a total concentration that is in the range ofabout 50 ppm to about 2000 ppm and the rebaudioside B is at a totalconcentration of at least about 20 ppm.
 8. The consumable of claim 7,wherein the rebaudioside B is at a total concentration of at least about50 ppm and no greater than about 500 ppm.
 9. The consumable of claim 7,wherein the rebaudioside B is at a total concentration of at least about100 ppm and no greater than about 400 ppm.
 10. The consumable of claim7, wherein the rebaudioside B is at a total concentration of at leastabout 200 ppm and no greater than about 300 ppm.
 11. The consumable ofclaim 5, wherein the consumable is selected from the group consisting ofa beverage selected from the group consisting of carbonated soft drinks,powdered soft drinks, ready to drink teas, sports drinks, dairy drinks,yogurt-containing drinks, alcoholic beverages, energy drinks, flavoredwaters, vitamin drinks, fruit drinks, and fruit juices; a foodstuffselected from the group consisting of baked goods, soups, sauces,processed meats, canned fruits, canned vegetables, dairy products,frozen confections, confections, chewing gums, cakes, cookies, bars, andother sweet bakery items, cereals, cereal bars, yogurt, energy bars,granola bars, hard candy, jelly candy, chocolate candy, and other sweetconfections; an oral care product selected from the group consisting oftoothpastes, mouthwashes, and oral rinses; a tobacco product selectedfrom the group consisting of snuff and chewing tobacco; a pharmaceuticalselected from the group consisting of tablets, lozenges, andsuspensions; a nutraceutical product selected from the group consistingof supplements and vitamins.
 12. The sweetening composition of claim 1,wherein the rebaudioside A is at a concentration that is no greater thanabout 85% by weight of the total amount of sweet steviol glycosidecompounds in the sweetening composition.
 13. The sweetening compositionof claim 1, wherein the rebaudioside A is at a concentration that is nogreater than about 80% by weight of the total amount of sweet steviolglycoside compounds in the sweetening composition.
 14. The sweeteningcomposition of claim 1, wherein the sweetening composition consistsessentially of sweet steviol glycoside compounds, wherein the sweetsteviol glycoside compounds provide essentially all of the sweetnessfunctionality of the sweetening composition.